Social network risk factors and COVID-19 vaccination: A cross-sectional survey study

•We surveyed 2,712 people in Canada following COVID-19 vaccine mandates in 2021.•Perceiving COVID-19 as less serious predicted reporting a mostly unvaccinated social circle.•Risk perception was a more powerful predictor than sociodemographic variables.•Risk perception may be a key indicator of social networks with lower intervention uptake.•Identifying high risk social circles has utility for outreach design and health system readiness. Social networks have an important impact on our health behaviours, including vaccination. People’s vaccination beliefs tend to mirror those of their social network. As social networks are homogenous in many ways, we sought to determine in the context of COVID-19 which factors were most predictive of belonging to a mostly vaccinated or unvaccinated social group. We conducted a cross-sectional survey among Canadian residents in November and December 2021. Participants were asked about the vaccination status of their social networks their beliefs relating to COVID-19, and various sociodemographic factors. Respondents were split into three groups based on social network vaccination: low-, medium-, and high-risk. Chi-squared tests tested associations between factors and risk groups, and an ordinal logistic model was created to determine their direction and strength. Most respondents (81.1 %) were classified as low risk (i.e., a mostly vaccinated social network) and few respondents (3.7 %) were classified as high-risk (i.e., an unvaccinated social group). Both the chi-square test (29.2 % difference between the low- and high- risk groups [1.8 % vs. 31.0 %], p